SPC May 8, 2025 1300 UTC Day 1 Convective Outlook

SPC 1300Z Day 1 Outlook

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0759 AM CDT Thu May 08 2025

Valid 081300Z - 091200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE
TENNESSEE VALLEY...SOUTHERN APPALACHIANS...SOUTHEAST AND THE RIO
GRANDE VALLEY OF TEXAS...

...SUMMARY...
Scattered thunderstorms with severe wind gusts and large hail are
expected today over parts of the Tennessee Valley, and southern
Appalachians, with hailstones greater than 2 inches in diameter
possible. Severe wind gusts and large hail will also be possible in
other parts of the Southeast, as well as West/South Texas including
the Rio Grande Valley.

...Tennessee Valley/Southern Appalachians to Southeast...
A positively-tilted mid-level trough, with an upper low centered
over the Ozarks this morning, will move through the Ohio and mid
Mississippi Valleys today, and toward the Appalachians tonight.
Surface dewpoints to the south of an advancing cold front will range
from the mid 50s to the mid 60s F. As surface temperatures warm
during the day, moderate instability is expected to develop with
minimal convective inhibition beneath relatively cool mid-level
temperatures via the proximity of the upper cold pocket. 

Storms will steadily increase into the afternoon with some
supercells and organizing clusters from western and central Kentucky
into middle Tennessee, eastward into the southern Appalachians.
These storms will develop south-southeastward into northern Alabama,
northern Georgia and the western Carolinas by late afternoon. Large
hail can be expected, with hail greater than 2 inches in diameter
possible especially with the more discrete and intense supercells.
Damaging wind gusts can also be expected regionally.

Another relatively favorable area for severe storms may focus across
southeast Georgia and nearby far southern South Carolina and/or far
north Florida this afternoon through early evening. This will be
coincident with somewhat stronger mid-level flow as compared to
areas farther south across the northern/central Florida Peninsula,
where isolated severe storms are still expected. Regarding northern
Florida this morning, see Mesoscale Discussion 738.

...West/South Texas including Rio Grande Valley...
A low-latitude shortwave trough will progress east-southeastward
across far northern Mexico and along the Rio Grande Valley today and
tonight. A corridor of moderate to strong instability will be in
place across the Rio Grande Valley. As surface temperatures warm
today, scattered thunderstorms are expected to develop in the higher
terrain of northern Mexico, with convection spreading eastward into
and across the Rio Grande Valley, potentially with multiple
rounds/corridors of severe weather possible across South Texas.
Regarding short-term severe potential across South Texas, see
Mesoscale Discussion 739. Strong deep-layer shear will contribute to
supercells capable of large to very large hail and damaging wind
gusts, especially if storms cluster/organize across the Rio Grande
Valley later this afternoon into evening.

..Guyer/Dean.. 05/08/2025

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